Tests requiring hackage-repo-tool don't run on Windows.

[grayjay]

I tried to run the tests that depend on hackage-repo-tool on AppVeyor, but I ran into several issues:

1. cabal-tests uses tar to create the repository, but tar misinterprets the colon in the drive letter, as in https://stackoverflow.com/questions/12823499/windows-command-line-tar-cannot-connect-to-d-resolve-failed-with-chef-knife/37996249. I was able to fix this issue by adding --force-local to the arguments in
   

   cabal/cabal-testsuite/Test/Cabal/Prelude.hs

   Line 480 in 59bb50b

   tar ["-czf", dst, "-C", src_parent, src_dir]

2. cabal-testsuite tests can access the Hackage package index on Windows #5187 prevents the tests from reading the repository settings from the test config file. Setting CABAL_CONFIG for each test seemed to work.

3. The repository url field in the config file generated by cabal-tests cannot be parsed as a URI. cabal-tests generates the config file here:
   

   cabal/cabal-testsuite/Test/Cabal/Prelude.hs

   Line 515 in 59bb50b

   , " url: file:" ++ testRepoDir env

   
   That produces a string with backslashes, such as file:C:\projects\cabal\cabal-testsuite\PackageTests\NewBuild\CustomSetup\LocalPackageWithCustomSetup\build-local-package-with-custom-setup.dist\repo. cabal parses the field as a URI in

   cabal/cabal-install/Distribution/Client/Config.hs

   Lines 1114 to 1117 in 59bb50b

   	remoteRepoFields =
   	[ simpleField "url"
   	(text . show) (parseTokenQ >>= parseURI')
   	remoteRepoURI (\x repo -> repo { remoteRepoURI = x })

4. cabal treats the file URI path as a file path when initializing the repository with hackage-security:
   

   cabal/cabal-install/Distribution/Client/GlobalFlags.hs

   Lines 248 to 249 in 59bb50b

   	withRepo _ callback | uriScheme remoteRepoURI == "file:" = do
   	dir <- Sec.makeAbsolute $ Sec.fromFilePath (uriPath remoteRepoURI)

   
   fromFilePath seems to expect a platform-specific path:
   https://github.com/haskell/hackage-security/blob/21519f4f572b9547485285ebe44c152e1230fd76/hackage-security/src/Hackage/Security/Util/Path.hs#L277-L281
   It converts the String to a FsPath, which contains a Path, which stores the path as a Posix-style path string: https://github.com/haskell/hackage-security/blob/21519f4f572b9547485285ebe44c152e1230fd76/hackage-security/src/Hackage/Security/Util/Path.hs#L121

   Later, hackage-security fails to find root.json, because it calls toAbsoluteFilePath on the invalid path:
   https://github.com/haskell/hackage-security/blob/21519f4f572b9547485285ebe44c152e1230fd76/hackage-security/src/Hackage/Security/Util/Path.hs#L322-L325 . toAbsoluteFilePath tries to convert the Absolute path back to the platform-specific format:
   https://github.com/haskell/hackage-security/blob/21519f4f572b9547485285ebe44c152e1230fd76/hackage-security/src/Hackage/Security/Util/Path.hs#L257-L258
   After I worked around (3), I saw that cabal/hackage-security converted the path of type Path Absolute, C:/projects/cabal/cabal-testsuite/PackageTests/NewBuild/CustomSetup/LocalPackageWithCustomSetup/build-local-package-with-custom-setup.dist/repo/root.json, to C:projects\cabal\cabal-testsuite\PackageTests\NewBuild\CustomSetup\LocalPackageWithCustomSetup\build-local-package-with-custom-setup.dist\repo\root.json. The result is invalid because it is missing a backslash after the drive letter.

5. After I worked around the previous issues, I saw new warnings about mirrors in the output, though I didn't look into them further.

    # cabal update
   +Warning: Caught exception during _mirrors lookup:user error (DnsQuery_A failed with 9003)
   +Warning: No mirrors found for file:///C:/projects/cabal/cabal-testsuite/PackageTests/NewBuild/CustomSetup/LocalPackageWithCustomSetup/build-local-package-with-custom-setup.dist/repo
    Downloading the latest package list from test-local-repo
   

EDIT: I think (5) was only caused by the changes I made to work around the other issues.

[grayjay]

I was able to run most of the hackage-repo-tool tests on AppVeyor with this commit: grayjay@d547107 I temporarily worked around the repo path issues by using a relative path, though I think that caused three of the new-freeze tests to fail.

Log: https://ci.appveyor.com/project/grayjay/cabal/build/1.0.507

There was one other test failure, PackageTests/NewBuild/CustomSetup/RemotePackageWithCustomSetup/build-package-from-repo-with-custom-setup.test.hs: https://ci.appveyor.com/project/grayjay/cabal/build/1.0.507#L1450